1. Field of the Invention:
This invention relates in general to semi-submersible marine craft or boats, and has specific reference to a semi-submersible marine craft adapted to be power-operated in both surface and semi-submerged conditions. The craft consists essentially of a pair of parallel spaced tubular floats disposed horizontally, symmetrically on either side of a vertical median plane, and of a central nacelle containing a power unit and a passenger's cabin.
2. The Prior Art:
Various types of marine craft, such as the so-called water-bikes or pedalled craft, have already been proposed for seaside leisure and amusement parks. A popular marine craft of this kind has a pair of parallel spaced floats of such length, cross-section and material that they impart the necessary buoyancy on water. Seats are arranged between the floats for the users who can thus assume a seated position in which they can efficiently actuate bike-like pedals driving either a paddle wheel or a screw disposed at the rear end of the craft. Thus, the craft is driven by the users' muscular energy. When the users get tired, they stop pedalling and the craft bobs up and down on the waves. These crafts, however, cannot be used for the observation of underwater marine fauna and flora.
The inconvenience of such known craft accounts for the increasing trend towards skin and scuba diving and underwater fishing, notably for the observation of marine fauna and flora by the divers. It is, however, necessary on the one hand to acquire the necessary diving equipment and on the other hand to have the physical fitness necessary for participating in these sports. Moreover, skin and scuba diving are both a hazardous sport. Divers must accordingly comply with safety regulations which in many cases are rather burdensome.
So-called "pocket" submarines used either for warfare or peaceful purposes in underwater exploration or various underwater interventions are also known. These submersibles cannot be used as instruments of leisure, since they call for considerable training of the users and also for a top physical condition.